There are two square-cut o'rings in the seal kit. These go into the recesses on the pump housing where the tank sits and seal the pump to the tank.
Install these then set the tank onto the housing, centering the holes in the tank to the holes in the housing. The tank sits on the pump with the return hose nipple towards the rear.
There is a heavy oblong metal piece with two holes in it. This sets down in the tank and the holes match up to the holes in the housing and tank. One of the holes in this piece has two metal tangs on the edge. This hole goes over the hole where the fluid goes into the pump, the tangs pointing upward.
Then there is the stamped metal cup the filter sets in. It sets over the blind hole with the tube for the return going through the small hole in the side of the cup.
Now the large nut goes through all those pieces and threads into the pump housing. Make sure before you do the final tightening that the heavy plate is still lined up on the other hole. The trick is to get all those pieces lined up, drop the nut into it and get it started in the hole without mis-aligning anything.
Some advice - the hole in the large nut is threaded for the bolt that holds the lid down on the tank. Since it is often hard to line these parts up when putting the top on, the threads in the nut and on the end of the bolt are often messed up enough to make it hard to get them aligned and started. Clean up the threads on both of these parts before you put things back together. It will make it much easier when you do.
Again, thanks for all your help! I've been out of town and not able to actually work on it. The car is a convertable and I won't be driving it for a few months anyway.
I was wondering which of the o rings go there. You cleared that up for me. It looks like the o rings that go in the housing around the shaft are also square cut. It that correct? I haven't been able to see where the round cut o rings go.